1. Field of the Invention
The present invention relates to allylalkylsilanes represented by the general formula(III) and their preparation methods by reacting allylsilanes represented by the formula I with olefin compounds represented by the formula II in the presence of hydrosilation catalysts such as chloroplatanic acid, platinum on silica, tributyl amine and Pd, Rh, Ni metals. ##STR3## wherein X represents independently chloro or alkoxy (C.sub.1 -C.sub.4) and R is selected from the group consisting of Ph, CH.sub.2 Cl, C.sub.n H.sub.2n CH.sub.3 (n=0-15), Si(Me).sub.m Cl.sub.3-m (m=0-3), CF.sub.3, CH.sub.92 CF.sub.3, CN, CH.sub.2 CN, ##STR4## CH.sub.2 Si(Me).sub.m Cl.sub.3-m (m=0-3), Si(Me).sub.m (OR.sup.1).sub.3-m (m=0-3), CH.sub.2 Si(Me).sub.m (OR.sup.1).sub.3-m (m=0-3) (wherein Me is methyl and R.sup.1 is methoxy or ethoxy group), Ph-CH.sub.2 Cl, and cyclohexenyl group.
2. Description of the Prior Art
Direct synthesis of allyldichlorosilane was first reported by Hurd in 1945. (D. T. Hurd, J. Am. Chem. Soc., 67, 1813 (1945)) When allyl chloride was reacted with a 9:1 Si--Cu alloy, a vigorous exothemic reaction occurred even at 250.degree. C. The condensate obtained contained trichlorosilane, tetrachlorosilane, allyldichlorosilane, diallyldichlorosilane, and allyltrichlorosilane predominating due to the decomposition of allyl chloride during the reaction. However, this reaction has never been used on a large scale in industry, because of the decomposition of allyl chloride and the easy polymerization of diallyldichlorosilane at high temperature above 130.degree. C.
Mironov and Zelinskii reported later that they obtained only 644 g of a mixture of allylchlorosilanes from the reaction of a 5:1 Si--Cu alloy with 2 kg of allyl chloride at 300.degree. C. The product mixture contained 356 g of allyldichlorosilane, 185 g of allyltrichlorosilane, and 103 g of diallyldichlorosilane. (V. M. Mironov and D. N. Zelinskii, Isvest. Akad. Nauk S.S.S.R., Otdel. Khim. Nauk 383 (1957)) The production of allyldichlorosilane and allyltrichlorosilane indicates that allyl chloride decomposed under the reaction conditions and dehydrochlorination or dechlorination were accompanied. This is why the yield was under 30%, indicating that the process was not economically feasible. ##STR5##
The present inventors reported a preparation method of allylchlorosilanes by directly reacting silicon metal simultaneously with allyl chloride and hydrogen chloride in the presence of copper catalyst at a temperature from 220.degree. C. to 350.degree. C. Allyldichlorosilane was obtained as the major product indicating one mole of each reactant reacted with the same silicon atom. When sufficient hydrogen chloride was added, diallyldichlorosilane was not formed. This eliminated the polymerization problem involved in the direct synthesis. (Korean Patent application No. 92-10292 (1992. 6. 13)) ##STR6##
Since the chlorine groups on silicon are easily hydrolyzed and give highly toxic hydrogen chloride, chlorosilanes are reacted with alcohol and converted to the corresponding alkoxysilanes. Allyldichlorosilane is reacted with alcohol to give hydrogen chloride and allyldialkoxysilane. If inert organic solvents are used in the reaction, less hydrogen chloride is dissolved in the product and less hydrolyzed by-products due to the water produced from the reaction of hydrogen chloride and alcohol are produced. The hydrogen chloride dissolved in the product will cause the cleavage of Si--H bond. In this reaction organic amines such as pyridine or triethylamine can be used to capture the hydrogen chloride in the products. (W. Noll, "Chemistry and Technology of Silicones" Academic Press, New York, 1968)
Si--H containing organosilicon comounds can be hydrosilylated with carbon-carbon unsaturated compounds and various organic groups can be introduced through hydrosilation. This hydrosilation can occur, but proceeds better in the presence of noble metal catalysts such as platinum, chloroplatinic acid. The most common catalyst is chloroplatinic acid which is used as a solution in isopropanol. In addition to platinum and palladium, inorganic compounds of nickel, rhodium, ruthenium, copper, and tin may be used depending upon the nature of the unsaturated organic compounds. The organic catalysts other than metallic or inorganic compounds such as triethyl amine, triphenylphoshine, and dimethylformamide may also be used. (E. Y. Lukevites and M. G. Voronkov, "Organic Insertion Reactions of Group IV Elements", Consultants Bureau, New York 1966) The most generally used catalysts are platinum catalyst such as chloroplatinic acid, platium on silica, and platinum on carbon.
Addition reactions of hydrosilanes to unsaturated compounds is initiated thermally, by radicals, and by catalysts. At temperatures of about 300.degree. C. without catalyst the hydrosilation occurs. Various organic peroxides which easily form free radicals have been used to initiate the hydrosilation. However, the thermal and radical reactions give many by-products and are not practical on a large scale. The hydrosilation proceeds better in the presence of noble metal catalysts such as platinum, palladium, etc.